Zero-Halogen Flexible Conduit

Zero-halogen conduit provides a low fire hazard solution for applications that require limiting toxic materials of combustion as they emit low amounts of non-toxic smoke in the event of a fire. Liquatite® offers six types: ZHLA, ZHLA-SS, CEA, HFSLA, HFEMS, and HFEMCS, each built with a low-smoke, zero-halogen thermoplastic jacket that have a low flame spread and self-extinguishing properties.

What Standards Does Liquatite® Zero-Halogen Conduit Meet?

All Zero-Halogen flexible electrical conduits fall well below the allowable maximums for the following standards:

• ASTM E162 for Flame Spread
• UL 94 & UL 360 for flammability
• ASTM E662 for low smoke generation
• Bombardier SMP800-C for toxic gas production

Why Choose Zero-Halogen Flexible Conduits?

These conduits support fire-safety requirements while maintaining superior flexibility and ease of installation. Zero-halogen options are built for high-risk environments ensuring safety and compliance.

Additional Benefits Include:

• Thermoplastic jackets that emit low amounts of non-toxic smoke
• Minimal flame spread for enhanced fire safety
• Self-extinguishing properties to reduce fire hazards
• Non-halogen emissions for compliance with safety-critical applications

Ideal Applications

Zero-Halogen flexible conduits are purpose-built for environments where fire safety and toxic gas control are vital, including:

• public transit stations
• trains
• tunnels
• elevators/escalators
• underground facilities
• heating & cooling equipment
• hospitals
• shipbuilding
• data centers

Which Zero-Halogen Conduit Type Should You Specify?

Zero-halogen is one of several specialty constructions in the Liquatite® flexible conduit line. The six types carry unique specialty features and benefits, for installation in a variety of applications.

Liquidtight Zero-Halogen Conduit

Types ZHLA, ZHLA-SS, and CEA are jacketed metallic liquidtight constructions in the LFMC family, so they provide safety in high risk environments with the LSZH jacket. ZHLA-SS is built on a stainless steel core, ideally suited for corrosive environments. These conduits are UL listed, except Type CEA offers a non-UL alternative.

Low-Smoke, Halogen-Free Conduit with EMI/RFI Shielding

Types HFSLA, HFEMS, and HFEMCS are halogen-free versions of Shield-Flex® EMI/RFI conduit, available in three levels of shielding effectiveness. Specify these where a run needs fire-safety performance and protection for sensitive signal or data lines at the same time.

Choose Liquatite® for Peace of Mind

When safety, compliance, and performance are non-negotiable, Liquatite® Zero-Halogen Flexible Conduits deliver.

From liquidtight flexible conduit systems to shielded constructions, our products are tested against the flame spread, smoke, and toxicity standards listed above.

Zero-Halogen Conduit FAQs

What is zero-halogen conduit?

Zero-halogen conduit uses a jacket compound formulated without halogens such as chlorine, fluorine, and bromine. When conventional jacket materials containing halogens burn, they can release corrosive gases and smoke. Zero-halogen compounds help reduce these hazards by producing less smoke and no halogen-based corrosive gases during combustion.

What does LSZH stand for?

LSZH stands for low-smoke, zero-halogen. The term describes a jacket compound that emits reduced smoke and no halogen acid gas during combustion. You may also see similar terminology written as LS0H (low-smoke, zero-halogen), LSOH (low-smoke, zero-halogen), or LSFH (low-smoke, free of halogen). LSZH conduit and zero-halogen conduit describe the same type of product, and our Type ZHLA and Type ZHLA-SS both carry the LSZH designation.

Is a halogen-free conduit the same as a low-smoke, zero-halogen conduit?

Not quite, though specifications often treat them as equivalent. Halogen-free refers only to composition, meaning the compound contains no halogens. Low-smoke, zero-halogen covers composition and burn behavior together, including smoke density. A compound can be halogen-free without published smoke data, so confirm which test results your project requires.

Why is zero-halogen conduit used in rail, transit, and tunnel applications?

In an enclosed transit environment, smoke and toxic combustion gas reach people before heat does, and both move faster than passengers can evacuate. NFPA 130, which covers fixed guideway transit and passenger rail systems, sets component combustion requirements around low smoke and zero halogen emissions, and NFPA 502 does the same for road tunnels. Zero-halogen conduit is specified so the conduit itself adds neither halogen acid gas nor dense smoke to the environment.

What standards does Liquatite zero-halogen conduit meet?

Our zero-halogen conduits fall below the allowable maximums for ASTM E162 for flame spread, ASTM E662 for smoke generation, Bombardier SMP 800-C for toxic gas production, and UL 94 and UL 360 for flammability.

Is zero-halogen conduit available in liquidtight and shielded options?

Yes. Liquidtight and shielded zero-halogen constructions are both available. If a single run needs liquidtight sealing and EMI/RFI shielding at once, your sales representative can confirm which type covers both.

Where should low-smoke, zero-halogen flexible conduit be specified?

Two conditions call for it: a space people cannot leave quickly, and equipment that has to survive a fire intact. The first covers transit stations, tunnels, trains, elevators, and underground facilities. The second is why data centers specify it, since halogen acid gas corrodes electronics long after the flames are out.

Learn more and download the Zero-Halogen Conduit Guide.